Off flavor

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Clifton

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I've brewed my first two BIAB recipes and both have a strange flavor in them. One taster described it as having the aftertaste of formaldehyde. The first one was Northern Brewer's Cream Ale recipe with Wy1056. I had a long lag phase (2 days) and I attributed my off flavor (astringent) to that. Now it has shown up in my second BIAB attempt, BM's Centennial Blonde (brewed with Wy1450). The Blonde had a shorter lag time, about 6 hours so that is not the culprit. The only thing they have in common is that both used the same base malt, canadian 2 row, and both were mashed low, I mashed in and walked away.

Any ideas where this flavor may come from?
 
Mashed how low? Did you previously brew extract or traditional all grain? If your previous process included mashing were your current brews completely different from your previous methods mash temp?

I'm thinking it tastes a little hot from the low mash temp. You didn't say so i assume you had good fermentation.
 
I previously brewed extract. The Cream ale I doughed in at 154, temp dropped to 148.8 so I added heat until I got to 150.4. I covered the kettle with a sleeping bag and walked away for an hour. Upon returning the temp was 146. I ferment in a temp controlled refrigerator. I had the temp set at 63 but fermentation didn't start so on the second day I raised it to 67. Finally had signs of fermentation after about 2.5 days. OG 1.041 FG 1.006.

The Blonde ale I doughed in at 154.7, temp dropped to 152. This time I didn't use the sleeping bag. I let it sit for an hour and tested for conversion. I pitched a 1 L starter of Wy1450 that was on a stir plate for 24 hrs and cold crashed for 24 hrs. I cold pitched and had airlock activity after 4.5 hours. Fermented at 65. I forgot to take OG but FG was 1.005.

Both batches used filtered (under sink carbon unit) municipal water. My water companies report doesn't give me much to work with so I don't know my total alkalinity.
Here is a link to it.
http://beckleywater.com/Documents/CCRReport.pdf
 
My father-in-law works for the water company. If I remember correctly, I don't think my water has chloramines.
 
If your FG was only 1.005 you have almost no sugars in there. Possibly not warm enough for the mash and sparge to draw the sugars out for your yeast. I usually mash right around 65-70c (149-158F)and sparge 70-75c (158-167F) to pull max sugars out without getting into the tannins. Was the yeast pack thin and once the food pack punctured? Did the package it swell up over the 3 hr rest time? If it was already swollen or did not inflate the yeast were dead. Regardless if there was no sugar in there they probably didn't last long. Not sure what they have in those packs for the booster but if there is any Artificial sweetener for the food it could contain Aspartame which would convert to Formaldehyde if it hit 86 degrees F, though I do not know that there would be enough to create that taste. Could be another bacteria got in there and out competed the yeast as well.
 
The cream ale was made from a frozen vial of yeast. The Blonde ale was from a smack pack of 1450. I made a starter and decanted into 4 vials, one vial was used to make a second starter that was used for the blonde ale.
 
Hard to say without post boil SG reading. Sounds more like another bacteria made it's way into the batch. Not aware of any known chemicals found in water that will give that flavor except the ones I previously mentioned. Almost has to be biological organism related. Someone else said it tasted like Formaldehyde, wonder if might have meant to say sulfur. How did the brew taste to you?
 
It is very hard for me to describe. It does come through in the aroma. I'll take another sample tomorrow and try to describe it. My first impression is astringent but it's not that because I can smell it in the foam of the beer.
 
I know I have high Calcium Bicarbonate levels but I'm not sure of the PPM. My water is a mixture to two sources. Sulfate is 8.4 and 69.4 at each source and Sodium is 32.5 and 146. I read somewhere that Sodium should be kept below 100 especially in the presence of Sulfate (usually best under 50ppm). Mine is likely higher that that. Could this be the cause of my harsh astringent type taste? The weird thing is that I can smell it. I read somewhere that old malt can cause off flavors. My base malt and water are the only two common denominators.
 
My problem may just be tannins. High carbonate content can lead to high mash Ph which can cause increased tannins. I always discounted tannins as a potential cause due to never getting close to 170 degrees. I never considered my Carbonate content. Does this sound possible/likely to anyone else? I'm still learning the AG ways.
 
I don't think it's Tannins since you have to get to 170+ to get into them. Even if you cross over that threshold a few degrees you would taste a tartness or maybe plastic taste if you got too much. At 158 that is a great temp to be at to get alpha and beta amylase sugars out of the grain and well withing the target to get what you want out of it. You didn't cover during the boil to get more of a green vegetable or cream corn flavor in there did you?
 
I actually think this is very likely to be some type of water problem, especially if it only showed up on all grain batches and not extract. Could be chloramines as I don't think a carbon filter removes them. But it sounds like you just may not have great water for what you are trying to brew - high bicarbonates is not good for light beers. It's not just temp that is a problem, pH is a big factor. From how to brew:

"The high alkalinity of the water makes it difficult to produce light pale beers that are not harsh tasting. The water does not allow the pH of a 100% base malt mash to hit the target range of 5 - 5.8, it remains higher and this extracts harsh phenolic and tannin compounds from the grain husks."

Unless you're brewing something like a stout you may have to dilute with RO water.
 
If your FG was only 1.005 you have almost no sugars in there. Possibly not warm enough for the mash and sparge to draw the sugars out for your yeast.

?? This doesn't make any sense. Are you confusing OG and FG? The beer finished at 1.005.
 
Yeah, I thought it was his post boil reading until I reread it and saw he did not take his post boil gravity reading. Figured 1.005, there's no sugar for the yeast to produce alcohol but that would probably be a way awful beer aside from the formaldehyde taste.
 
Nope, 1.005 was my FG.

I actually think this is very likely to be some type of water problem, especially if it only showed up on all grain batches and not extract. Could be chloramines as I don't think a carbon filter removes them. But it sounds like you just may not have great water for what you are trying to brew - high bicarbonates is not good for light beers. It's not just temp that is a problem, pH is a big factor. From how to brew:

"The high alkalinity of the water makes it difficult to produce light pale beers that are not harsh tasting. The water does not allow the pH of a 100% base malt mash to hit the target range of 5 - 5.8, it remains higher and this extracts harsh phenolic and tannin compounds from the grain husks."

Unless you're brewing something like a stout you may have to dilute with RO water.

I think this is it. High carbonates, sodium, and sulfates. I'm planning on brewing the Blonde again and I'll dilute with half distilled water.
 
Activated carbon filters or Campden tablets will remove chloramines. I've narrowed by astringent aftertaste down to chloramines or the ph being to alkaline. The unfortunate thing about cholramines is that the ppm's don't have to be high to notice the taste.
 
Clifton, sounds like a good plan, that will cut your alkalinity in half and lower the pH a bit. Without a water report or a pH reading, you’re shooting in the dark.

There are three things that you have to watch regarding tannins.

1. Sparge Temp- Most people say less than 170 F.
2. Runoff Gravity- Stop before 1.010
3. Sparge pH- Stay below 6.0

For astringency I always recommend RO or distilled sparge. That pretty much guarantees your sparge pH will be within limits, drastically limiting tannins. It's the quickest and easiest thing you can try.

AMD, you’re partly right about the activated carbon and chloramine removal. It works, but it takes FOREVER. If I remember correctly, mabrungard estimated .1 gallon/minute. As it takes a really tiny amount of chlorine to wreck a batch, why screw around?
 
Clifton, sounds like a good plan, that will cut your alkalinity in half and lower the pH a bit. Without a water report or a pH reading, you’re shooting in the dark.

There are three things that you have to watch regarding tannins.

1. Sparge Temp- Most people say less than 170 F.
2. Runoff Gravity- Stop before 1.010
3. Sparge pH- Stay below 6.0

1. Shouldn't be the issue.
2. Shouldn't be the issue becaulse both were BIAB.
3. Sparge shouldn't be the problem because both were BIAB, but Mash PH could've been too high.

AMD, you’re partly right about the activated carbon and chloramine removal. It works, but it takes FOREVER. If I remember correctly, mabrungard estimated .1 gallon/minute. As it takes a really tiny amount of chlorine to wreck a batch, why screw around?

I definitely filtered faster than .1 gpm. Did you mean Chloramine? I'm 90% certain my water has no Chrolamines.
 
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